In recent years, the display resolution on mobile devices has advanced significantly to where 720 p or even higher super liquid crystal display (LCD) displays or organic light emitting diode (OLED) displays are mainstream for smart phones and tablets. However, such high display resolutions typically require much more energy for rendering, especially for video where high frequency frame buffering and display panel refreshing are indispensable.
For LCD displays, power consumption is often a monotonic function of the backlighting brightness level. For OLED displays, power consumption is often controlled by the supply voltage as well as the display content itself. While brightness control is already implemented on some mobile devices, those controls typically must be adjusted prior to issuing a new job, meaning before starting playback of a video. For example, brightness may be set at 100%, 50%, or even 25% prior to watching a video, but the brightness cannot be changed dynamically without interrupting playback of the video. In addition, since power consumption is determined by the supply voltage and input image for OLED displays, current implementations do not provide a mechanism for adapting the supply voltage.
In one prior approach, backlight scaling based on image RGB components has been performed. However, such methods have been designed for still images and result in flicker when applied to videos. Note that an RGB component is a single sample representing one of the three primary colours of the RGB colour space which is a colour space based on the red, green and blue primaries. In some embodiments, pixel intensities may be used instead of RGB components.